copper with hypo?

[bunk97]

Is it bad to use copper while doing hypo? I would think so but just want to make sure. Has anyone used the swingarm to do hypo I know it is not good to use these but I really can't afford a refracometer right now but still want to do hypo. Is it possible to use the swing arm hydro?
thanks
humahuma

 

[beth]

There is no point to exposing your fish to copper unless absolutely necessary. Thus, don't use copper unless you have to.
Get a glass hydrometer and it for hypo. You can get a refract online for about $70. Well worth the money, IMO.